Even on the high school level you get kids who would love to see things
explode. Basically if I get a piece that seems to thick, or was not put
together in a well crafted manner, I do the following:

1. Take a pin and prick a lot of holes in it in the inside before it dries.
2. Let it dry twice as long as anyone else's. (when the kid wants to know
why it is taking longer to fire their pot, I tell them I am being cautious
because it is thick, or I watched them put it together and their
craftsmanship was questionable, but I will fire it).
3. I fire all of the 'questionable' ones together in the kiln, and if that
is not possible, I put the thick ones on the bottom, shelf over them before
I put in the other pieces. If the pieces explode the shelf acts like a
'ceiling' and the pieces don't 'rain down' on other pieces.
4. Have the student whose piece exploded help me clean out the kiln. Let
them realize that all the little pieces that once was their pot, have to be
removed before you can fire again. (Again, I treat this like a potter's
studio experience, not as a punishment. As a potter, you would have to clean
out your kiln).

San D

Haha! If I used wedging clay as a punishment, a few kids would probably
purposefully wedge air INTO the clay! I'm amazed how every year a few
kids are obviously dying to add an air pocket to their clay stuff just
to see what happens when it explodes in the kiln.